help please...hardwiring a garmin 2720...or similar

[argentifa]

hi...got a bit of a problem here....and my head is starting to hurt...

..im trying to hard wire the garmin into my car.....mainly because I'd like to get the audio out on the satnav to play through the car stereo...

..so, iv bought a 12v fm modulator (audio then goes into the radio via a series connection by the car aerial)

i disconnected the speaker wires in the garmin cigar plug/speaker unit and fed them directly into the audio input into the 12v modualtor..which then connects it back up to the radio..

now in theory, if i tune the radio to the same frequency as the modulator...i should get audio out through the car stereo system... no?

trouble is Im getting excessive modulation...a bit like signal overload....and im a bit unsure how to fix it....

any ideas?

...please...?

[mikealder]

You are feeding too high a voltage (volume) into the FM modulator, as a first step try setting the output volume on the Garmin to the minimum it will allow, if this still over drives the input you will need to attenuate the signal, this is not to easy and would require an additional circuit to interface between the two devices - Mike

[argentifa]

Thanks for that Mike..

I did set the vol on the garmin to the minimum...but I still got loads of "modulation" interference.

I also have the motorcycle mounting lead....(going to fit it to the bike when ive got time..) what i don't understand, is that the audio output on the unit is the same one for both the car & the motorcycle ...

and given that the motorcycle lead will work with an earpiece, in theory it should work with the modulator...it's designed for mp3 players etc...

strange eh?

[FM-in-MI]

[TurnerTech]

Your solution seems a bit over engineered.

Why not get a Loudspeaker matching transformer (I do not know the correct name) and connect it to your loudspeaker. Connect the Garmin earpiece jack to the other side of the transformer circuit and you should have what you need for a cople of quid without needing (illegal) RF transmitters.

Talk to a hifi buff. These transformers are used a lot in matching amplifiers to loudspeaker impedences. Try Maplins.

Then once the circuits are matched, the Garmin onscreen volume control will let you chose the required setting.

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!